This invention relates to sortation systems, and more particularly to a sortation system which utilizes a series of carriers movable on a track, wherein the track includes a series of sortation stations and the carriers deposit items at the sortation stations, for sorting the items into individual orders or the like.
Various types of sortation systems are known, and are typically used in connection with order fulfillment, returns processing, mail sortation, or any other application in which different items are to be sorted according to certain parameters. One such system utilizes carriers, in the form of trays, mounted to a track. The trays are connected together in train-type fashion, and are moved along the track in any satisfactory manner, such as by use of a chain drive mechanism or the like. Individual receptacles are placed at sort stations at discrete locations along the length of the track. When the tray arrives at a sort station which requires the item carried by the tray, a discharge arrangement functions to discharge the item from the tray and into the receptacle, such as by means of a chute located at the sort station. The tray may include a false bottom, which is opened when the tray reaches the desired sort station such that the item or items carried by the tray fall into the chute and are deposited into the receptacle. The tray then advances on the track to close the false bottom of the tray, and a subsequent item is placed into the tray for sortation into another order or the like.
Systems of this type typically operate continuously, and at a relatively high rate of speed. Typically, items are placed within the trays at an induction station, wherein the item is identified and is advanced to its desired sort station by the drive mechanism. In this type of system, photoelectric sensors are provided along the length of the track in the vicinity of each sort station, and provide inputs which count the trays as the trays are advanced along the track. A pneumatic actuator is typically provided at each sort station, for tripping a discharge mechanism associated with each tray so as to allow the contents of the tray to drop from the false bottom of the tray. While this type of system functions satisfactorily to sort items, such systems are expensive and time consuming to construct and install. The photoelectric sensors require power supply wiring as well as interconnection with a controller that receives the inputs from the photoelectric sensors. The pneumatic actuators require both power supply wiring as well as a source of pressurized air, at each sort station. A common system has several hundred sort stations, and thus requires a significant amount of time, material and expense to construct and install. Further, systems of this type require the trays to be connected together so as to enable the trays to be reliably counted and to thereby provide accuracy in depositing the correct items in the correct order receptacles. If the system is operated so that all trays carry an item to be sorted, system throughput is unacceptably slow and causes a bottleneck in the overall process. Accordingly, systems of this type are operated at a relatively high rate of speed to increase overall throughput. However, it is common for many trays to be empty when being transported along the track, due to the inability of the induction mechanism or operator to keep up with the speed of operation and place one or more items in each tray. While the speed of operation of the trays maintains throughput at an acceptable level, this type of system is inefficient in that many trays are transported empty through the system.
It is an object of the present invention to provide a sortation system which is generally similar to the type of system described above, providing carriers movable on a track with sort stations at various discrete locations along the track. It is a further object of the invention to provide such a system which eliminates the need for photoelectric sensors and pneumatic actuators, and thereby the required communication wiring as well as pressurized air supply to each sortation station. It is a further object of the invention to provide such a sortation system which can be operated at a slower speed, yet which provides the same or greater throughput than prior art systems by reducing the number of carriers which are empty during operation. A still further object of the invention is to provide such a sortation system which is capable of asynchronous operation, in that the carriers are movable on the track independently of each other. A still further object of the invention is to provide such a sortation system which is highly accurate and reliable, ensuring that the correct items are placed into the correct orders. Yet another object of the invention is to provide such a system which is easy to operate, and which can be used in connection with any type of induction system.
In accordance with the present invention, a sortation system includes a track arrangement having a series of sort stations, and a series of carriers movable on the track arrangement. The carriers are adapted to receive items destined to be deposited at the sort stations. Each carrier includes an actuable item discharge arrangement, for discharging the item or items from the carrier.
Each sort station includes an actuator and a unique identification arrangement. Each carrier is provided with a destination identification according to the identity of the item contained within the carrier. Each sort station actuator and identification arrangement interacts with the carriers, to determine whether the sort station is the destination sort station for the carrier. If so, the sort station actuator is selectively operated to actuate the item discharge arrangement of the carrier, such that items carried by the carrier are discharged from the carrier at the predetermined sort station, according to the identity of the items carried by the carrier. The carriers are movable on the track arrangement independently of each other. The identification features associated with the carriers and the sort stations are in the form of a wireless transceiver system which operate the sort station actuators to actuate the actuable item discharge arrangement of each carrier when the carrier reaches its destination sort station. The transceiver system includes a sort station signal emitter at each sort station, which emits a unique sort station identification signal corresponding to the location of the sort station, which may represent an order being filled by items transported on the carriers along the track arrangement. The transceiver system further includes a receiver interconnected with a programmable memory as associated with each carrier. The programmable memory is programmed with a destination identification according to the item(s) carried by the carrier, and the receiver receives the unique sort station identification signals as the carriers are moved past the sort stations. A simple program associated with each carrier processes the received sort station identification signals for comparison against the destination identification, to ascertain whether the sort station is the destination sort station for the carrier. If not, the carrier continues its movement along the track arrangement to the next sort station, where the operation continues until the carrier reaches its destination sort station. When the destination sort station is reached, the program associated with the carrier functions to transmit an actuation signal to the transceiver associated with the destination sort station, which is processed by the actuator so as to operate the actuator to actuate the item discharge arrangement of the carrier and to discharge the one or more items from the carrier at the destination sort station, and into an order receptacle located at the destination sort station. The carrier then continues its movement along the track arrangement to an induction station. A passive reset arrangement is located along the track arrangement upstream of the induction station, for closing the false bottom of the carrier in preparation for receiving another one or more items to be sorted at the induction station.
Each carrier is provided with its own source of power, such as a battery power supply, which provides power to the transceiver associated with the carrier. The actuator associated with each sort station includes a trip mechanism, which is movable between an operative position into the path of the carrier, and an inoperative position withdrawn from the path of the carrier. In the operative position, the trip mechanism engages the actuable item discharge arrangement of the carrier, for discharging items carried by the carrier at the destination sort station.
The invention also contemplates a method of sorting items as well as an improvement in an item sortation system, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.